Key Idea: Mill defends one rule for a free society: the harm principle — power may be used against a person only to prevent harm to others, never merely for their own good. From it he builds a strong defence of free speech, individuality and protection from majority pressure. This text is assessed on Paper 2, a 25-mark open-book essay on the studied text. You study On Liberty in full.
🧠 The four moves, one card each
10.12 at a glance
- 10.12.1 · The harm principle — The one rule of the book: society may interfere with a person's liberty only to prevent HARM TO OTHERS. Your own good — physical or moral — is never a sufficient reason to coerce you. The hard part is where 'harm to others' begins.
- 10.12.2 · Liberty of thought and discussion — No opinion should be silenced. If it is true, we lose truth; if false, we lose the sharpening that comes from meeting it; if partly true, we lose part of the picture. Unchallenged truth decays into 'dead dogma'.
- 10.12.3 · Individuality — People should be free to live in their own way — 'experiments in living'. Custom followed blindly stunts human development; a good life is one you actively choose, not one merely inherited.
- 10.12.4 · The tyranny of the majority — Freedom is threatened not only by governments but by SOCIAL pressure — opinion and custom that punish difference. This 'tyranny without a tyrant' can be more suffocating than law, and the harm principle limits it too.
The harm principle: the only reason to use power over someone against their will is to prevent harm to others — never for their own good. Free speech, individuality and the fight against majority tyranny are all applications of this single rule.
✍️ Bring it together — a Paper 2 question
Evaluate Mill's harm principle as the sole legitimate ground for limiting individual liberty.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Using your text in the open-book exam
- Bring a CLEAN copy — IB rule: your text must be UN-annotated — no notes in the margins, no underlining or highlighting. A marked-up copy is not allowed in the exam. Check it well before the day.
- Know the map — You have the book, but not time to read it. Memorise WHICH chapter carries each theme — harm principle (ch. 1), liberty of thought (ch. 2), individuality (ch. 3), limits of society (ch. 4) — so you can find a passage in seconds. Keep your study notes in a SEPARATE document.
- Quote to evidence, then EVALUATE — Use the open book to cite a line precisely so it backs a specific point — then argue about it. Never let a quotation replace your own analysis; a copied passage with no evaluation earns little.
- Plan then write — A quick argument map — position, support, objection, weighing, conclusion — beats flipping pages mid-essay. Decide your line first, then dip into the text for evidence. Watch the clock.
Important: Retelling the book instead of evaluating it. Listing Mill's three arguments for free speech, however accurately, is not an answer to 'Evaluate'. You must weigh the claim — strongest support, strongest objection, then a reasoned decision. The open book also punishes inaccurate use of the text: cite precisely, and don't confuse the harm principle (harm to OTHERS) with a ban on all restriction.
✅ Check yourself
If you can answer these six, you have the spine of the whole text.
State the harm principle. Power may be used over an adult against their will only to prevent harm to OTHERS — never merely for their own good.
Why never silence an opinion? If true we lose truth; if false we lose the sharpening of meeting it; if partly true we lose part of the picture.
What is 'dead dogma'? A true belief held unthinkingly, never challenged, so its meaning and force fade — the cost of silencing dissent.
What are 'experiments in living'? Mill's phrase for freely trying out different ways of life; individuality and progress need them, not blind custom.
What is the tyranny of the majority? Freedom crushed not by law but by social pressure — opinion and custom that punish difference, a tyranny with no tyrant.
What is the main objection to the harm principle? That 'harm to others' is vague (offence, self-harm, indirect harm) and that some paternalism seems clearly justified.
Exam Tips
- Paper 2 is a 25-mark OPEN-BOOK essay on this one text — the marks are for evaluation, not for how much of the book you can recall.
- Bring a clean, un-annotated copy and know which chapter carries each theme so you can cite fast.
- Quote precisely to evidence a point, then argue about it — never let the text speak for you.
- Always weigh the strongest case each way and end on a reasoned conclusion, not a summary.